Add bp2build converter for cc_genrule.

Test: cc_genrule_conversion_test.go

Change-Id: I19290b417d6336020a15ba7fa772ee0c76c58225
diff --git a/cc/genrule_test.go b/cc/genrule_test.go
index 45b343b..b6afb05 100644
--- a/cc/genrule_test.go
+++ b/cc/genrule_test.go
@@ -23,7 +23,7 @@
 
 func testGenruleContext(config android.Config) *android.TestContext {
 	ctx := android.NewTestArchContext(config)
-	ctx.RegisterModuleType("cc_genrule", genRuleFactory)
+	ctx.RegisterModuleType("cc_genrule", GenRuleFactory)
 	ctx.Register()
 
 	return ctx